5 psi is here....and I'm not impressed

[paul_oz]

Do you have a Blow Off Valve? If so, is it stuck open, releasing the turbo pressure ?

[MarkEmark]

Do you have a Blow Off Valve? If so, is it stuck open, releasing the turbo pressure ?

Yep, I got a blow off valve. No, it's not stuck open, it works quite nicely...I'm jsut about to go test the other turbocharger I just "threw" on...i'll let ya know how she purrs.

[s13sr20chris]

If his turbo doesn't satisfy me, I'm either a) gonna give up and just not care anymroe Marc

not acceptable my friend. sorry to get in here late. test the new turbo. i should have come earlier and told you to get another. garret turbos are dirt cheap. even new ones. it sounds to me like you either have crappy turbo syndrome or whack a/f syndrome. your cams should be just fine; dont mess with them. you need an intercooler. personally i dont thing turbos should ever be run without an intercooler. ever. just my opinion. i hate to stress your budget, but try going to a dyno with wideband o2 capability. i think that will help out a lot. there you have it. two things to check. please dont quit. the fact is any nissan engine is better than a darn 1.8t. volks/audi suck in my opinion. the diff between your car and your brothers is that he bought a well engineered product and you are engineering your own. keep it up and your car will be faster; not because you are a better engineer than the team of professional that hooked up your bro, but because you are driving a nissan with a nice KA in it. who will be more satisfied? the audi guy(your bro) that just plugged a piece up to his car, or the nissan guy(you) who built his own turbo setup from the ground up for less overall(including the price of his car)? you will be. man, dont be another victim of nissan quirkiness. love the quirks. i love nissan and nissan only(well i also love my wife). nissan is the best.

[MarkEmark]

Where are you getting those pressure drops from? I'd expect a very slight decrease in pressure at the compressor to the pressure at the TB...but negligible decreases (like 0.25 psi). For 7 psi....THeres no way the intercooler takes robs 2 psi. Go to jgstools.com...there intercooler only has a 0.625 psi pressure drop, and that's at HIGH boost...naturally it will be less of a drop for less boost (the pressure drop is a function of the flow across the intercooler-more flow/cooling = more pressure drop).

I think I might skip the intercooler for a while...at least until I can FIND one that will fit without hacking my bumper, I've had horrible luck. However, I will be installing an alcohol-injection kit...which works wonders at preventing detonation.

Marc

[AceInhole]

hmm.... what do you have for spark plugs? what's the gap set at??Is it possible your BOV is leaking under boost (what BOV is it anyways?)?Anyways, if you're getting boost drop due to the intake piping, then run the WG vacuum line from the manifold, or even from anywhere close to the TB. The boost should level off that way. The exhaust might also help. The boost drop-off (with the WG line still tapped to the turbo housing) was a lot less, and I gained like .5psi after getting the Greddy DD.

I run a smaller turbo than you do, and get a good amount of power from it. At 6psi we timed (off of a video) 0-60 to be 5.3sec (the only measure of power I have....).

[MarkEmark]

I'll try measuring boost pressure off of the intake manifold/close to the TB...any idea what lines I should "tap" into?

Since I'm not running an i/c (at least not for a while), I'm going to make a MUCH more direct, less convoluted route from the turbo compressor to the TB, which should help a bit...also, my intake will soon be cold air, which will add some power....

At 7 psi w/alc injection/cold air intake/more direct compressor to tb piping, it should feel damn nice...

I took it out yesterday at 6.5 psi and It felt pretty nice...

[SloS13]

I asked a while ago for you to check your plugs. Did you do that? Plugs can tell you a lot

[MarkEmark]

I guess you missed the part where I said I was using a very efficient ALCOHOL INJECTION SYSTEM. That'll prevent detonation as much as any intercooler will. Plus, I always use 94 octane gas. I measured intake temperatures right near my TB with a dig. thermometer at 6.5 psi and found them to only get as high as 150, and they usually hovered around 140...with 90 degree ambient air. It's not worth $400 for me to buy an intercooler, which even at 100% efficiency will only lower the intake temperature by 50/60 degrees. Hence alcohol injection...for now. What size spearco are you using?

If your spearco is dropping the pressure by 2 psi when you're at 7/8 psi, then there's somethign seriously wrong. Lowering the temperature even 100 degrees wont make up for a 2 psi pressure drop.

Yes, I'm reading mine off of the line that goes from the BOV to a "t" connection, whose other port goes to the FPR...I want one directly tapped into the intake manifold/TB.

[:: orion ::]

I would not run a turbo ka WITHOUT an intercooler.. Thats asking for detonation unless you have a SUPER efficient turbo..

Not so...

People always think an intercooler is an ABSOLUTE necessity of a turbo system...

But run the #s...

At 85-degrees ambient, with a turbo boosting 8psi in a 70% efficiency range...the outlet temps will theoretically be 187-degrees F. So w/o an intercooler, the engine sees 187 F...

Then, with the same ambient temps and same efficiency, boosting 25psi BUT using an intercooler (with a generous 75% efficiency rating)...the outlet temps would be 327 F, and the intercooler would cool it by 181 F, leaving the motor to see 145-degrees F...but at a MUCH higher overall cylinder pressure due to the increased boost (3X as much).

And none of us would have a problem running the 25psi (with a built motor, and the right amount of fuel and tuning, etc...) - But you say an extra 40-degrees F is asking for it. I say the extra cylinder pressure from the 17psi of boost is more likely to detonate, but it doesn't.

So why does an extra 40 F add so much danger...it doesn't.

Sure, you'd find ~7% more power with the same intercooler at the 8psi setup...but the detonation level isn't reduced as much as we'd all like to think it is.

EDIT: Oh yeah - Here's the basis for the numbers above:http://www.gnttype.org/techare....html

Just some food for thought...

Later - Brian

[MarkEmark]

Thanks for the GOOD information....

I guess my turbo isn't very efficient, at 6.5 psi, as I said, it would only go up to 150 degrees, usually around 140...and I'm not goin above 7 psi, so alc injection should be fine. Again, eventually I will get an intercooler when money allows/I find the exact one I want, but I'm not about to drop $400 for somethign that cools the air only 50 degrees....However, for cheaper, I can lower the temperature going into the turbo inlet by about that much by making it cold air...which is what I'm doing tomorrow.

I had new piping made up that went straight from the compressor to the TB and had a bung welded in for the alc injection nozzle...this new piping is 1/2 the length of the old piping and has 1/2 of the bends...much more efficient, should be good for at least quicker spool/better throttle response.

Marc

[JustinM]

Off tOpiC... Still using the factory ECU?

[aaronsnocker1]

Why do you keep comparing your turbo ka to your brothers 1.8t Audi. If it is not fast enough go spend the 20 grand or so and buy one or quit complaining and appreciate the fact that when you are done and getting full power you will smoke his a**. Hang in there and think about what you will say to him when you win.

[MarkEmark]

Hey guys....this topic was posted on July 30th..it's now November 6th. Since then I've sorted out some problems, have gotten a bigger turbo, cranked the boost up to 9 psi, and I can smoke his a$$ no problem.

Topic should be closed...Yes, stock ECU

[rco8786]

I don't know what the turbo came off of, I thin it was off of an older 300zx. All that I'm running so far for a fuel system is a Bosch RRFPR...I'll be installing a better fuel pump soon, but I haven't been running rich or lean, it seems to be running perfect the way it is. No heat problems; I installed a really nice oil cooler and thermostat to try to help out w/ the extra heat.

Vuse1...my list of things I needed to turbo my car is no different than anyone elses....there's a bunch of FAQ's on this forum about what you need to do it...

mARC

Same turbo I have...too bad I still need a manifold. So, two questions.

1) When does that turbo spool? 2) What manifold are you using?

[rco8786]

Hey guys....this topic was posted on July 30th..it's now November 6th. Since then I've sorted out some problems, have gotten a bigger turbo, cranked the boost up to 9 psi, and I can smoke his a$$ no problem.

Topic should be closed...Yes, stock ECU

My bad

[MarkEmark]

The T3 that I did have on it (.48/.42 turbine/compressor) was phenomenal for throttle response, and built boost INSTANTLY. Not a single hint of lag whatsoever, you jumped on it, it made boost...it boosted VERY early. However, it ran out of juice past 4K RPM pretty dramatically---it'd go from 8 psi to about 5 psi after 4k RPM which made the car feel REAL weak on the top end, despite its copious amount of torque. I switched to a brand new T3 Super 60B, .48/.60, and it cured the problem of losing boost past 4k rpm, it boosts full boost all the way up to 5500 RPM, and while it has a bit more lag than the older turbo, the difference is negligible and more than made up for by the consistent boost in high RPM. I am very happy with the turbo on it right now, very quick throttle response, spools up pretty quickly, and keeps boosting up in the rev range. i'd recommend it to any KA guys.I'm just using a regular log manifold (JGS style), 2.5" straight exhaust, high flow cat.

[fiznat]

hey Mark where are you from in CT again? I thought I asked you before but maybe not. I'm from Middletown... I'd LOVE to get a ride in your car sometime if you wouldnt mind. Email me if you get the chance: [email protected] or catch me on AIM at "foosternit"

[AceInhole]

this makes me wonder if I should actually go for that M10 turbo for $70, .48 exh, .63 comp, looked like small trim wheels tho....... Although, I've been pretty happy with my TD05-12B +S13 cams. VERY linear power.

Anyways, I noticed the "Autocross" avatar you have, Mark. Where the hell do you autocross? CART, BMW club, and the Ford Club are the only ones I know of around here that I don't race with...... I run with NER, NESCC, and FCSCC. Pretty much fills my season.

Fiznat: too bad I didn't check this earlier. I'll be up near Boston today picking up some Hoosiers and a 5pt harness.

[MarkEmark]

I'm in Somers (north central, bordering with massachussetts at longmeadow).

AceInHole--about the avatar---I haven't actually autocrossed before (yep, I'm a wicked poser), I just want to REALLy bad...I'm only 17 right now--and I'm pretty sure you have to be 18 to autocross. Anyay, I will plan on doing it come spring, however, as I've wanted to try it for the longest time. I also want to do a track day at limerock once I turn 18 (february).

For the autocross, I know connecticut has an autocross club...this is the website: http://www.cartct.com/

So i guess that's the same CART you're referring to.

Any advice on where I should start?Also, what the hell class do you run in? I have a host of modifications done to the suspension, transmission, and engine...

[MarkEmark]

Fiznat--I see that you're now in Boston Mass, and your email says @bu.edu.How do you like it up there? I just visited BU last weekend, along with BC with my brother and my mom, and a good friend of mine across the street has a brother in BU who seems to love it.What are you majoring in/what year are you?

Marc

[AceInhole]

AceInHole--about the avatar---I haven't actually autocrossed before (yep, I'm a wicked poser), I just want to REALLy bad...I'm only 17 right now--and I'm pretty sure you have to be 18 to autocross. Anyay, I will plan on doing it come spring, however, as I've wanted to try it for the longest time. I also want to do a track day at limerock once I turn 18 (february).

yeah... try to get in with SERCA or NASA when they do track days there. Probably might be best to even do an HPDE so you're instructed your first time out.You don't need to be 18 to autocross. Under 16 they have karts, 16 - 18 you just need a parent's permission. A written letter or permission is good enough.

Quote »For the autocross, I know connecticut has an autocross club...this is the website: http://www.cartct.com/

So i guess that's the same CART you're referring to.[/quote]we had trouble getting across that parking lot the one time we went to a CART event (That they cancelled because not enough people attended). Ask ANY other group: FCSCC, NER, NESCC, BMW Club, Porsche Club, etc.... and they'll say they don't like CART's autocrosses that much.

Check out:http://www.fcscc.comhttp://www.ner.orgh ... .nescc.org

And especially check out http://forums.240sxone.com

Quote »Any advice on where I should start?Also, what the hell class do you run in? I have a host of modifications done to the suspension, transmission, and engine... [/quote] Of those groups, NER has the best Novice program. For autocrossing, it's probably the best in the NorthEast.Most likely you'll run in the same class as me: Street Modified. You can pretty much do ANY suspension mod, ANY engine mod (as long as you have ANY Nissan/ Infiniti engine). You can run ANY brakes. Interior must be intact, except the rear seat may be removed.

Most of the 2003 rules can be found here:http://www.moutons.org/sccasol....html